Ihara I, Harada Y, Ihara S, Kawakami M
J Immunol. 1982 Mar;128(3):1256-60.
It has been shown that nonimmune mouse sera contain a complement-dependent bactericidal factor that reacts specifically with Ra chemotype Salmonella. In this study we investigate a specific determinant to which this factor binds. This factor bound to Ra chemotype lipopolysaccharide (LPS) but not to S or Re chemotype LPS. The binding was markedly inhibited by N-acetyl-D-glucosamine (GlcNAc), which was the nonreducing terminal of the Ra polysaccharide chain and by certain monosaccharides structurally relating to L-glycero-D-mannoheptose, a terminal component of a side branch of Ra polysaccharide. The factor bound to the Ra bacteria could be eluted with a medium containing GlcNAc. These results indicate that the specific determinant is the polysaccharide region of LPS characteristic of Ra chemotype Salmonella. Ca2+ but not Mg2+ was required for the specific binding of the factor to cells of Ra bacteria. A molecule composed of a polypeptide of 28,000 m.w. was found in the active fraction obtained by the monosaccharide elution. However, no polypeptides corresponding to light and heavy chains of mouse immunoglobins were detected from the active fraction.
已表明非免疫小鼠血清含有一种补体依赖性杀菌因子，该因子与Ra化学型沙门氏菌发生特异性反应。在本研究中，我们调查了该因子所结合的特定决定簇。该因子与Ra化学型脂多糖（LPS）结合，但不与S或Re化学型LPS结合。N-乙酰-D-葡萄糖胺（GlcNAc）可显著抑制这种结合，GlcNAc是Ra多糖链的非还原末端，某些与L-甘油-D-甘露庚糖结构相关的单糖也可抑制这种结合，L-甘油-D-甘露庚糖是Ra多糖侧链的末端成分。结合到Ra细菌上的因子可用含有GlcNAc的培养基洗脱。这些结果表明，特定决定簇是Ra化学型沙门氏菌LPS的多糖区域。该因子与Ra细菌细胞的特异性结合需要Ca2+而非Mg2+。在通过单糖洗脱获得的活性组分中发现了一种由分子量为28,000的多肽组成的分子。然而，从活性组分中未检测到与小鼠免疫球蛋白轻链和重链相对应的多肽。
